1. Field of the Invention
This invention relates to antioxidants, and more particularly, to new intermediate compounds, and their use for synthesizing novel stabilizing organic compounds which are effective against thermo-oxidative degradation.
2. Description of the Prior Art
It is known to employ derivatives of sterically hindered phenols as stabilizers for plastics against thermo-oxidative degradation or degradation induced by light. However, many of these compounds do not afford long life protection against these degradative effects, and others exhibit the disadvantage that they discolor the organic polymer in an objectionable manner either when they are incorporated or under the action of light or on contact with industrial flue gases or even on contact with hot water, which greatly limits their applicability in industry. Now new compounds have been found which, surprisingly, are outstandingly suitable for stabilizing organic polymers.
The prior art is represented by such U.S. patents as U.S. Pat. Nos. 3,057,928; 3,210,428; 3,275,597; 3,354,118; and 4,132,702; and Belgium Pat. No. 652,510.
3. Relates Copending Patent Applications
(a) FDN-215, Ser. No. 062,761, filed Aug. 1, 1979, describes and claims novel antioxidant compounds, and organic material stabilized with their aid.
(b) FDN-215/B, Ser. No. 062,763, filed Aug. 1, 1979, describes and claims a method of making the said intermediate and antioxidant compounds.